Heat the oil in a large pot over medium high heat. Season the ribs with salt and pepper to taste and dredge them in flour. Fry the ribs in the oil in small batches, adding oil as needed, to sear the meat. This should take 2 to 3 minutes per batch. Set ribs aside.
In the same pot, add the onions and saute for 2 minutes. Add the celery and carrots and saute for 1 more minute. Season with salt and pepper to taste, and then stir in the garlic, bay leaves and thyme and cook for 1 more minute.
Deglaze the pot with the beer, scraping up all the bits on the bottom. Add the stock, bring to a boil, reduce heat to low and simmer. Add the ribs and continue to simmer for 2 hours, until the beef starts to fall apart. Remove the beef from the pot and set aside. Strain out the veg, keeping the sauce. Reduce the sauce by half. Add to beef. Stir in the parsley and serve with potatoes of your choice.